[Transarterial Embolization of Intraorbital Dural Arteriovenous Fistula:A Case Report].

Intraorbital dural arteriovenous fistula(dAVF)is a very rare disease; therefore, an optimal treatment strategy has not yet been established. Here, we describe a case of successful dAVF treatment by performing transarterial embolization(TAE)with n-butyl-2-cyanoacrylate(NBCA). A 66-year-old male presented with right conjunctival injection, with no history of trauma. Magnetic resonance imaging(MRI)demonstrated a flow void in the right orbit. Digital subtraction angiography(DSA)revealed an AVF fed by a branch of the right ophthalmic artery(OA)and draining into the dilated right superior ophthalmic vein(SOV). A transvenous embolization(TVE)was planned, but it could not be performed because the facial vein was meandering. Hence, TAE with NBCA was performed, and the AVF was successfully occluded by this method. There has been no recurrence of intraorbital dAVF in three months since the treatment. Several recent studies have reported that TAE is an effective treatment for intracranial dAVF. However, there are insufficient reports of TAE with NBCA for intraorbital dAVF treatment. The anatomy of the OA needs to be known for the success of TAE in treating intraorbital dAVF, because TAE is a high-risk treatment. In this paper, we report a case wherein TAE with NBCA was performed for intraorbital dAVF and further review the other treatment options.

Dynamic contrast-enhanced perfusion MR imaging with SPIO: a pilot study.

PURPOSE: To investigate the feasibility of dynamic susceptibility-weighted contrast material-enhanced (DSC) perfusion imaging with ferucarbotran at 3.0 T, and to assess the impact of the different characteristics of gadolinium (Gd)- and ferucarbotran-based agent in rCBV measurement under pathologic condition with BBB disruption. MATERIALS AND METHODS: Nine patients with suspected meningioma (4 men and 5 women; age range, 27-79 years; mean age, 61.6 +/- 17.9 years) were eligible for the study. Approval was obtained from the institutional review board. All participants provided signed informed consent prior to the study. DSC perfusion images were acquired with a T2*-weighted echo-planar imaging sequence during the first pass of a standard-dose of Gd-based agent, and of 4, 8, or 16 micromol Fe/kg of ferucarbotran-based agent in 3 patients for each dose respectively. Pre- and postenhanced T1-weighted images were obtained in all. RESULTS: Ferucarbotran decreased the signal intensity in both gray and white matter in a dose-dependent fashion. Differences regarding the DeltaSI between the 4 and 8 or 8 and 16 micromol Fe/kg groups were statistically significant (P < 0.05, 1-way analysis of variance, Tukey-Kramer method) in any region. No effect of leakage of ferucarbotran was demonstrated in the intensity-time curves or in the postenhanced T1-weighted images. Relative CBV in tumor area obtained with Gd was reduced to 37.6%-86.5% compared with that obtained with ferucarbotran. CONCLUSIONS: T2*-weighted DSC perfusion imaging with ferucarbotran is feasible at 3.0 T. Compared with Gd-based agent, larger particle size of ferucarbotran can diminish the effect of contrast leakage during the first pass under pathologic conditions with BBB disruption.

Proton magnetic resonance spectroscopic imaging integrated into image-guided surgery: correlation to standard magnetic resonance imaging and tumor cell density.

OBJECTIVE: In this study, we attempted to improve the delineation of the infiltration zone in gliomas using proton magnetic resonance spectroscopic imaging (1H MRSI). In conventional magnetic resonance imaging (MRI), the boundaries of gliomas sometimes are underestimated. 1H MRSI is a noninvasive tool that can be used to investigate the spatial distribution of metabolic changes in brain lesions. The purpose was to correlate tumor cell density from histopathological specimens with metabolic levels and the coregistered metabolic maps. METHODS: We developed a method to integrate spectroscopic data depicted as metabolic maps of biochemically pathological tissue into frameless stereotaxy. In seven patients harboring gliomas, we performed 1H MRSI with high spatial resolution and evaluated the spectral data. An algorithm was developed for user-independent calculation of pathological voxels and for visualization as metabolic maps. These maps were integrated into a three-dimensional MRI data set used for frameless stereotaxy. Stereotactic biopsies were taken from three different areas in and around the tumor involving the maximum pathological change, the border zone, and an area from outside the spectroscopically suspicious area. These specimens were correlated to the exact voxel positions in the stereotactic image space and evaluated histopathologically. RESULTS: In all cases, the implementation of the metabolic maps into frameless stereotaxy was successful, and stereotactic biopsies were acquired by use of the spectral data. A relation could be demonstrated between the metabolic changes and tumor cell density ranging from 60 to 100% in the maximum pathological area to 5 to 15% in the border zone. Interestingly, the tumor areas defined by the metabolic maps and histopathologically confirmed by biopsy exceeded the T2-weighted signal change in all cases, ranging from 6 to 32% in the examined volume. CONCLUSION: Our preliminary data suggest that 1H MRSI may be useful in combination with frameless stereotaxy to define more exactly the tumor infiltration zone in glioma surgery compared with conventional anatomic MRI alone.

[Combined imaging of epileptic foci and brain metabolism using MEG and FDG-PET].

A 17-year-old woman developed left hemiparesis at the age 6 months. She had suffered from focal motor seizures associated with tonic extension of her left extremities since the age of 10 years. The interictal scalp EEG demonstrated frequent spike-and-slow-wave complexes dominantly in the right frontal area. MRI showed an old cerebral infarction in the right frontal lobe. Simultaneous recordings of magnetoencephalography (MEG) and EEG were obtained by using a 204-channel whole-head MEG system. Equivalent current dipoles (ECDs) calculated from epileptic spikes on MEG were scattered in the cortex adjacent to the lesion in the right frontal lobe. Positron emission tomography with 18-fluoro-2-deoxyglucose (FDG-PET) in the interictal state showed hypometabolism in the lesion and its adjacent area. The super-imposed images of the dipole and PET showed that epileptic foci surrounded the lesion. The multimodality imaging is useful for evaluation of patients with epilepsy for possible indication of surgery.